bin/53313: tmux regression: scrolling with ctrl+b/ctrl+f is broken in 8.0

[nia.alarie%gmail.com@localhost]

>Number:         53313
>Category:       bin
>Synopsis:       tmux regression: scrolling with ctrl+b/ctrl+f is broken in 8.0
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 26 00:45:00 +0000 2018
>Originator:     nia
>Release:        8.0 RC1
>Organization:
>Environment:
>Description:
Pressing ctrl+[ then ctrl+b should scroll the tmux buffer backwards one page.

This behaviour works as expected in NetBSD 7 and current.

It does not work in NetBSD 8.
>How-To-Repeat:
Attempt to scroll backwards with ctrl+b in tmux in NetBSD 8.
>Fix: